Warren wrote:


Is your question "how long before I need to replenish some nutrients?", or
is it "how long before I need to add fertilizer?" Those are two different
questions. The second is far narrower than the first, and the answer to the
second often can be "never".

It's like asking how long before a person needs to take a vitamin pill. Some
people live long lives without ever taking a vitamin pill. And a vitamin
pill doesn't necessarily mean that someone in need of nutrition will get
what they need.

Fertilizers are the vitamin pill of the plant world. There are situations
that are so foreign to the normal culture of a plant that the only way
they'll get nutrition is with fertilizer, but even if fertilizer is the only
way to get then the nutrients they need, it would still be possible to
overdose them.

There are so many variables, and you can't just start plugging values into
the equation, and solve it like it's a math problem. And even if you could
reduce the needs of a particular plant down to a theoretical number, that
doesn't address the delivery method. Fertilizer may not be the right way to
deliver those nutrients. Maybe compost is. Maybe repotting is. Maybe
different watering methods will allow nature to resolve the problem.

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That helps. I thought fertilizer was like the meat and potatoes of a
plant's diet, rather than just a vitamin.